1. Field of the Invention
The present invention relates to a display apparatus and a display method used, for example, for a navigation system and, in particular, to a technology for controlling a direction of display of a character string displayed on its display screen.
2. Description of the Related Art
A car navigation system which is mounted on a vehicle has been hitherto known. By this car navigation system, a driver can drive a car while checking his car position by looking at a map displayed on the display screen of a display apparatus, so the driver does not lose his way but can arrive at his destination without fail and in a short time.
The conventional car navigation system like this has a north-up mode of a map display in which the north is always displayed upward and a heading-up mode of a map display in which the direction of travel is always displayed upward as a mode of displaying a map on the display screen. In the heading-up mode, when the direction of travel of the vehicle is changed, for example, at a crossroad or a curved road, the contents of display screen are rotated as a whole along with this change in the direction of travel of the vehicle. Hence, characters and symbols displayed on the map are also rotated.
In general, when roads on the displayed map are designated by names, character strings constructing the names are displayed along the roads (in order to be in parallel to the roads). Hence, when the character strings are rotated along with the rotation of the whole contents displayed on the display screen, there is bought about a state where the character strings are displayed in an inverted position when viewed from a driver depending on a rotation angle. Since the display apparatus is mounted at the center of vehicle, whether or not the character strings are displayed in an inverted position when viewed from the driver, differs according to the position of driver's seat, that is, whether the vehicle is a left-hand drive vehicle or a right-hand drive vehicle.
In this regard, as a related art have been known a menu screen display method by which the switch operating part of a menu screen displayed on a monitor is displayed at a position closer to a passenger's seat side when the part is operated from the passenger's seat side and is displayed at a position closer to a driver's seat side when the part is operated from the driver's seat side, and a display apparatus using the method (see, for example, patent document 1).
Moreover, a navigation apparatus has been known which is provided with a display control unit for controlling a screen display in such a way that a driver can easily look at and operate the screen of a display unit from the driver's seat, at which a steering wheel is mounted, on the basis of the positional relationship between a position where the steering wheel is mounted and the display unit, thereby improving visibility and operability relating to the display unit from the driver's seat and further improving visibility and operability relating to the display unit also in response to an operation from the passenger's seat (see, for example, patent document 1).    [Patent document 1] Japanese Unexamined Patent Publication No. 2001-222271    [Patent document 2] Japanese Unexamined Patent Publication No. 2003-121160
As described above, the display apparatus of a car navigation system in the related art presents a problem of bringing about a state where while the display apparatus is being operated in the heading-up mode, the character strings displayed on the map are rotated and displayed in the inverted position along with the rotation of map displayed on the display screen, thereby making the characters hard to read.